package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IVoucherService;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private RedissonClient redissonClient;

    @Override
    public Result seckillVoucher(Long voucherId) {
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        LocalDateTime beginTime = voucher.getBeginTime();
        if (beginTime.isAfter(LocalDateTime.now())) {
            return Result.fail("秒杀还没有开始！");
        }

        LocalDateTime endTime = voucher.getEndTime();
        if (endTime.isBefore(LocalDateTime.now())) {
            return Result.fail("秒杀已经结束!");
        }

        Integer stock = voucher.getStock();
        if (stock < 1){
            return Result.fail("库存不足!");
        }
        Long userId = UserHolder.getUser().getId();
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        boolean isLock = lock.tryLock();
        if (!isLock){
            return Result.fail("不允许重复下单");
        }
        Result voucherOrder;
        try {
            voucherOrder = createVoucherOrder(voucherId);
        } finally {
            lock.unlock();
        }

        return voucherOrder;
    }

    @Transactional
    public synchronized Result createVoucherOrder(Long voucherId) {
        Long userId = UserHolder.getUser().getId();
        Integer count = query().eq("user_id", userId)
                .eq("voucher_id", voucherId).count();

        if (count>0){
            return Result.fail("你已经抢购过优惠券！");
        }


        boolean isUpdate = seckillVoucherService.update()
                .setSql("stock=stock-1")
                .eq("voucher_id", voucherId)
                .gt("stock",0)
                .update();

        if (!isUpdate) {
            return Result.fail("库存不足!");
        }

        VoucherOrder voucherOrder = new VoucherOrder();
        voucherOrder.setVoucherId(voucherId);
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);

        voucherOrder.setUserId(userId);
        save(voucherOrder);

        return Result.ok(orderId);
    }
}
